A. Field of the Invention
The present invention relates generally to quality of service guarantees and, more particularly, to systems and methods for providing packet loss service-level guarantees for data network communication.
B. Description of Related Art
In the highly competitive Internet service provision industry, service-level guarantees (SLGs) have become an extremely important market differentiator. The trend in SLGs has included a movement toward service contracts that attach financial penalties to failures to meet certain key network performance criteria. Since the industry remains in a state of flux, service providers must constantly extend and revise their SLGs to compete. As a result, service providers face the dilemma of formulating meaningful performance criteria to attract and retain business, while avoiding imposing a financially ruinous burden on the company.
An important aspect of SLGs is compliance monitoring. Currently, SLGs are reactive in the sense that customers must monitor performance and submit a claim when they experience poor service. At the same time, however, the service provider must monitor its own performance, both to make sure that sufficient resources are available and its SLGs are met, and to verify and validate customer claims.
A typical SLG criteria includes the measurement of end-to-end packet loss (i.e., a measure of packet drops between a source and a destination). Conventional systems measure packet loss using dedicated Internet Control Message Protocol (ICMP) packets. These conventional systems send ping packets to a reliable target and determine the round-trip packet loss rate from the fraction of unacknowledged pings.
Using ICMP to measure packet loss, however, has several disadvantages. First, packet characteristics, such as size and frequency, used to measure the packet loss typically do not correspond to the packet characteristics of the customers"" data traffic. Second, finding reliable targets to ping is not always easy. Third, routers are usually unreliable because they give low priority to responding to pings during busy periods.
As a result, a need exists for a system that facilitates measurement of packet loss to validate customer SLG claims.
Systems and methods consistent with the present invention address this need by using readily-available performance data, such as link-level drop statistics, to measure end-to-end packet loss and validate customer SLG claims.
In accordance with the purpose of the invention as embodied and broadly described herein, a system monitors performance in a network having several routers. The system determines a path in the network between a source and a destination, identifies routers located on the path, collects performance data from the identified routers, and compares the performance data to at least one performance criteria to determine compliance with a service-level guarantee.
In another implementation consistent with the present invention, a method validates customer claims relating to performance in a network having several routers. The method includes receiving one of the customer claims, the claim identifying a path in the network between a source and a destination and a time interval for which degraded performance was experienced; identifying routers located on the path; collecting performance data from the identified routers for several periods, at least some of the periods overlapping the time interval; weighting the performance data based on an amount of overlap of the corresponding period with the time interval; combining the weighted performance data for each of the identified routers to obtain path performance data; and determining compliance with a service-level guarantee based on the path performance data.
In a further implementation consistent with the present invention, a method for validating a claim relating to a service-level guarantee includes receiving the claim from a customer, the claim identifying a first path in a network from a source to a destination, a second path from the destination to the source, and a time interval for which degraded performance was experienced in the network; and validating the claim by collecting performance data reflecting performance of communication along the first and second paths and determining compliance with the service-level guarantee based on the collected performance data.